This invention relates generally to an arrangement for measuring the momentum transfer spectrum of elastically scattered X-ray quanta and a method of determining the momentum transfer spectrum measured in the arrangement.
An apparatus for the examination of items of luggage is described in EP 1 241 470 B1. Such an apparatus has a focus extended in Y-direction which emits X-radiation in X-direction. Through a primary collimator extending in Y-direction only X-ray quanta which are aimed at a single isocentre are passed through into an examination area behind the isocentre. The isocentre forms the originating point of a Cartesian coordinates system and a disk-shaped inverted fan beam is thus formed. A scatter collimator system which is developed annularly about the Z-direction is arranged between the isocentre and the examination area. The result is that only scattered radiation from an object located in the examination area is passed through which emanates from the scatter voxel at a fixed preset angle of scatter. A detector which extends along the Z-axis is arranged in the Y-Z plane. Depth information regarding the scatter voxel, i.e. its X-coordinate, is thereby imaged onto a parallel of the Y-axis in the Y-Z plane. By means of such an arrangement a rapid analysis of an item of luggage can be achieved, with only a one-dimensional movement of the item of luggage along the Z-direction on a conveyor belt. The scanning speed is, however, limited by the angle-dependent sensitivity of the detector elements.